Red River Basin Stage-Damage Curves Update and Preparation of Flood Damage Maps

To achieve more accurate flood damage estimates in the Red River Valley, the development of a stage-damage model needs to consider the spatial and temporal impact of flooding. KGS Group was contracted by the International Joint Commission to perform a study that would update existing stage-damage (depth-damage) relationships and incorporate them into a methodology to map potential flood damages in the Red River Valley resulting from a repeat 1997 and 1826 flood event. The development of updated depth-damage relationships, and the various data sources were compiled through the use of a GIS and database model. The GIS/Data model computes structural damages by relating damage to the depth of flooding at the first floor while considering existing flood protection infrastructure. Damages to civil infrastructure were computed by relating the density of infrastructure works (primarily roads) within the flooded area to a damage function developed from reported damages. Agricultural losses are calculated based on the expected crop yield reductions resulting from a delay in seeding.